Hydrological, chemical and biological processes of transformation and transport of contaminants in aquatic environments : proceedings of the Hydrochemistry 1993 Symposium held at Rostov-on-Don, Russia, 24-29 May 1993 : the Symposium was jointly organized by the Russian IHP National Committee, UNESCO and the IAHS International Commission on Water Quality (...) / edited by Norman E. Peters, Rod J. Allan, Vladimir V. Tsirkunov.